Brain has more "computer power" than thought
Neuroscientists at the University of North Carolina have found that dendrites - the short branches that project from neurons and carry nerve signals – may actively process information instead of passively carry it from neuron to neuron.
Previous research discovered many of the same molecules that support electrical spikes are also present in the dendrites, and experiments with brain tissue showed dendrites can use these molecules to generate these spikes themselves. However, it was unclear whether normal brain activity involved “dendritic spikes,” and, if so, what role they might play.
To find out, lead author Spencer Smith and his colleagues attached tiny glass pipes known as pipettes to dendrites in areas of the mouse brain responsible for processing data from the eyes. The researchers then took electrical recordings from individual dendrites within the brains of anesthetized and awake mice. As the mice viewed black-and-white bars on a computer screen, the scientists detected an unusual pattern of electrical signals, or bursts of spikes, in the dendrites. And the electrical signals from the dendrites varied depending on the features of the images the mice saw. This, said researchers, suggests that the dendrites may actually help the mice process what they see.
All in all, “functions we thought required an entire neuron may be carried out instead by just one portion of a neuron’s dendritic tree,” Smith told LiveScience. “This would imply that a single neuron can act like many, many computational sub-units.” He also noted that although his research focused on understanding how brain circuitry works, it also might help address brain disorders as well.